The glass industry supports an estimated 500,000 people.
It is an industry that has improved over the years and can match European standards today - thanks partly to new technology and partly to a Supreme Court order.
After the apex court ordered the closure of coal-based glass furnaces in 1993, glass industries are now being run on natural gas, supplied by the Gas Authority of India Ltd (GAIL) through its pipeline network.
One advantage of this switchover to gas has been the vastly improved performance of the plants in terms of productivity.
This change has naturally led to an increase in exports and helped Firozabad present a new modernistic profile.
Devi Charan Agarwal of Bajrang Glass International said: "The improved quality of production has helped us compete in the international market. Glass units in Firozabad are definitely poised for dramatic growth as a result of the modernisation process brought about by the switchover to natural gas."
Girdhari Lal Mittal of Ramdoot Bangles pointed to the reduction in the overall pollution in Firozabad. The incidence of tuberculosis has gone down as consumption coal has been banned in the bigger units.
"The factories are cleaner as there is no smoke."
Right now around 100 glass units are using natural gas. Of these, 10 are engaged in exports. Only a small number of smaller units are now using firewood and coal.
Production costs have come down to almost half, though the glass manufacturers say "there has been a reduction of around 10 percent in costs and an increase of 15 percent in production".
The pot furnaces, which cost up to Rs.4 million to fabricate, earlier had to be repaired annually. But now, because of the use of natural gas, the repairs need to be done once in three years, which means a huge saving.
Lalitesh Jain, director of the Glass Syndicate, told IANS that although GAIL had not been meeting the full demands for gas of Firozabad, "there was little doubt about increased productivity and vastly improved quality of products".
With improved technology and higher productivity, the face of the town is changing.
"A few years ago, there were chimneys all over, countless numbers, all belching smoke and fire. In the summer evenings the city was enveloped in a thick cloud of black smoke, making breathing difficult," according to Shyam Sunder, an industrialist of Shikohabad, 15 km away, who is trying to secure a gas connection for his factory.
"Thanks to Supreme Court and GAIL, the whole scene has changed for the better," he said.